Your calculation is off by 10^6 -- I think you mixed up m/s with km/s? Also the air density should be far lower -- at your altitude (53 km) it's 7.2e-4 kg/m^3 o

Your calculation is off by 10^6 -- I think you mixed up m/s with km/s? Also the air density should be far lower -- at your altitude (53 km) it's 7.2e-4 kg/m^3 or so. I don't think streamlining makes much difference at hypersonic speeds -- air molecules will hit your craft regardless of how it's shaped, there's no time push them out of the way. So a drag coefficient of 0.02 isn't likely; it's probably at least 1. You could look up stuff on spacecraft reentry to find more accurate figures. https://www.wolframalpha.com/input/?i=density+air+53+km https://www.wolframalpha.com/input/?i=density+air+53+km Put together, I get something like 2 million Newtons or 200 tonnes force. This is about half the thrust of SpaceX's Falcon 9, so clearly this won't work. https://www.google.com/search?q=(7.2e-4+kg%2Fm%5E3+%2F+2)+*+(7+km%2Fsecond)%5E2+*+130+meters%5E2 https://www.google.com/search?q=(7.2e-4+kg%2Fm%5E3+%2F+2)+*+... https://en.wikipedia.org/wiki/Falcon_9 https://en.wikipedia.org/wiki/Falcon_9 The drag power at this speed is 16 gigawatts, which needs about 100 square kilometers of solar panels. https://en.wikipedia.org/wiki/Drag_(physics)#Power https://en.wikipedia.org/wiki/Drag_(physics)#Power https://www.google.com/search?q=(7.2e-4+kg%2Fm%5E3+%2F+2)+*+(7+km%2Fsecond)%5E3+*+130+meters%5E2 https://www.google.com/search?q=(7.2e-4+kg%2Fm%5E3+%2F+2)+*+... Another problem: at this altitude, a sphere with a 130 m^2 cross section has a lifting power at most 0.8 kg (the mass of the displaced air). https://www.google.com/search?q=4%2F3+*+pi+*+(130+m%5E2+%2F+pi)%5E(3%2F2)+*+7.2e-4+kg%2Fm%5E3 https://www.google.com/search?q=4%2F3+*+pi+*+(130+m%5E2+%2F+... This really won't work.